Bunk bed



FIG. 1 is a front, upper perspective view of a bunk bed of my new design;

FIG. 2 is a front view of the bunk bed of FIG. 1;

FIG. 3 is a rear view of the bunk bed of FIG. 1;

FIG. 4 is a right view of the bunk bed of FIG. 1;

FIG. 5 is a left view of the bunk bed of FIG. 1; and,

FIG. 6 is a top view of the bunk bed of FIG. 1.

The broken lines in the figures illustrate portions of the bunk bed that form no part of the claimed design. 

CLAIM The ornamental design for a bunk bed, as shown and described. 